WASHINGTON - A new best-selling book about U.S. President Donald Trump, his decision-making and his administration went on sale to the public Tuesday.

Investigative journalist Bob Woodward's Fear: Trump in the White House is a highly critical look at Trump's chaotic 20-month presidency.

Woodward has written books about seven prior administrations and gained journalistic fame nearly five decades ago as one of the Washington Post reporters whose investigative stories about White House corruption helped drive President Richard Nixon from office.

Former Washington Post reporter Bob Woodward speak
Former Washington Post reporter Bob Woodward speaks during an event sponsored by The Washington Post to commemorate the 40th anniversary of Watergate, June 11, 2012 at the Watergate office building in Washington.

But he told NBC that until Trump he had "never seen an instance when the president is so detached from the reality of what's going on."

Trump criticized the book ahead of its release, calling it a "joke" and "just another assault against me, in a barrage of assaults."

The book has already risen to No. 1 on Amazon's best-seller list, but Trump said Woodward used "now disproven unnamed and anonymous sources. Many have already come forward to say the quotes by them, like the book, are fiction. Dems can’t stand losing. I’ll write the real book!"

The Woodward book is a Joke - just another assault against me, in a barrage of assaults, using now disproven unnamed and anonymous sources. Many have already come forward to say the quotes by them, like the book, are fiction. Dems can’t stand losing. I’ll write the real book!

In a related issue, she said Trump continues to have "great concern" about last week's anonymous opinion article by a top administration official published in The New York Times accusing the president of being amoral and being "impetuous, adversarial, petty and ineffective."

She said the Justice Department should "look into it," and then decide whether any crimes were committed. She joined other administration officials in calling for the aide to quit, but said no lie detector tests "are being used or talked about" in an effort to identify the writer.

In one of a string of Twitter comments, Trump said, "Bob Woodward is a liar who is like a Dem operative prior to the Midterms," claiming the author "was caught cold, even by NBC" in an interview on the network's Today show about his use of unnamed sources to recreate behind-the-scenes events at the White House since Trump took office in January 2017.

“It is mostly anonymous sources in here, why should anyone trust you? General Mattis, General Kelly said it’s not true.” @SavannahGuthrie@TODAYshow Bob Woodward is a liar who is like a Dem operative prior to the Midterms. He was caught cold, even by NBC.

Trump retweeted himself from last week, saying, "The Woodward book is a scam. I don’t talk the way I am quoted . If I did I would not have been elected President. These quotes were made up. The author uses every trick in the book to demean and belittle. I wish the people could see the real facts - and our country is doing GREAT!"

The Woodward book is a scam. I don’t talk the way I am quoted. If I did I would not have been elected President. These quotes were made up. The author uses every trick in the book to demean and belittle. I wish the people could see the real facts - and our country is doing GREAT!

Asked by NBC why readers should trust his account using anonymous sources, Woodward said: "The incidents are not anonymous. It gives a date, it gives a time, who participates, most often the president himself and what he says."

The 75-year-old Woodward said that at a National Security Council meeting a year into Trump's presidency, when he was complaining about the cost of posting thousands of U.S. troops in foreign countries, Secretary of Defense Jim Mattis had to explain the rationale to him.

"We're doing this to prevent World War III," Woodward quoted Mattis as telling Trump. "The idea that a secretary of defense has to tell the president that all of these actions are designed to prevent the ultimate catastrophe and then Mattis goes on and says, you know, that if we don't keep these programs, which are very sensitive, the only deterrent option we have would be the nuclear option."

From left, U.S. Secretary of State Mike Pompeo, Se
From left, U.S. Secretary of State Mike Pompeo, Secretary of Defense James Mattis and national security adviser John Bolton listen as U.S. President Donald Trump meets with NATO Secretary General Jens Stoltenberg at the White House in Washington.

The author quoted White House chief of staff John Kelly as calling Trump an "idiot" and telling a staff meeting in his office, "We're in crazytown," and Mattis as saying that Trump had an understanding of world affairs of something akin to a "fifth- or sixth-grader," quotes they both have denied.

"They're not telling the truth," Woodward said. He called their denials "political statements to protect their jobs, totally understandable."

But he said his book "is as carefully done as you can do an excavation of the reality of what goes on" in the Trump White House.

He described the current and former Trump officials who talked to him as "people of conscience, people of courage who said, 'Look, the world needs to know this.'"

Woodward said the officials believe, like former Trump economic adviser Gary Cohn said, "Got to protect the country."